As will become apparent, the invention has wide interconnect applications, and will, for example, find important interconnect uses such as those in the three dimension, printed wiring board (3D PWB) industry. One application that is illustrative, however, for which a preferred embodiment of the invention is particularly suitable, is in serving interconnection functions in electrostatographic reproducing machines. Recently, in order to minimize maintenance costs by permitting the operator to replace worn out or exhausted processing units in electrostatographic apparatus, emphasis been placed on incorporating one or more processing units of the apparatus in disposable or removable cartridges or units. In this way the operator can readily remove each cartridge when its operational life has been exhausted and insert a new cartridge. In addition, it also provides the advantages of providing for easier service and diagnostics access to the internal subsystems of a reproducing machine and enabling less expensive functional features.
In these applications, it is necessary to distribute power and/or logic signals between the various units, subsystems, and/or cartridges of the machine. Traditionally, this has been accomplished utilizing conventional wires and wiring harnesses in each machine to distribute power and logic signals between, for example, the main frame of the machine and a removable processing unit or a subsystem unit. For instance, conventional plug and socket arrangements have been used which can be either manually connected or joined automatically on insertion of the unit into the main frame. Such automatic joining requires precision positioning and alignment of the unit on insertion with very low tolerance for error. Typically locating members such as pins or rails are used to insure proper positioning, all of which adds to the manufacturing cost of the machine. In addition, conventional wires and wiring harnesses are flexible and therefore, do not lend themselves to automated assembly such as with the use of robots further leading to increased manufacturing costs.
Presently, many types of interconnects, particularly high voltage connectors, are routinely manufactured by insert molding a preformed metal pin or socket into an insulating plastic housing. Often a suitable wire is simultaneously insert molded within the same connector housing to produce a complete connector assembly. There are, however, at least three to five separate steps to manufacture conventional high voltage connectors.
Moreover, in many typical copies systems, it is desired to provide a flexible interconnection between wires of different assemblies, circuit boards, or other members in the system. Such flexible interconnects have been accomplished in the past by such techniques as flexible ribbon wires with plugs that attach to mating plugs on the members to be interconnected. Such ribbon wiring arrangements, however, do not lend physical support between the interconnected members, and also often involve intensive labor fabrication requirements. Furthermore, such harnesses may have to be handled or moved several times to make all connections required. This is a highly labor intensive task, frequently requiring routing of the several harnesses through channels and around components manually with the final connections being also accomplished manually, thereby resulting in potential human error in the assembly, which might be reduced with the use of automated and in particular robotic assembly. In addition to the relatively high labor costs associated with electrical harness construction and installation, it is well to note that such wiring harnesses are less than totally reliable in producing their intended function. Furthermore, and with increasing sophistication of the capabilities of such products, a plurality of wiring harnesses may be required in any individual machine which can require a large volume of space thereby increasing the overall size of the machine. Accordingly, there is a desire to provide an alternative to the conventional wiring and wiring harnesses that overcomes these difficulties.
While certain other types of electrical contacts have been proposed, they suffer certain deficiencies. For example, the use of two conventional metal plate contacts such as two spring biased metal tabs, for instance, one on a main frame and one on a removable unit, in addition to requiring the precision positioning and alignment discussed above can be rendered unreliable after only a short period of use in a hostile machine environment, as might be encountered in a reprographic copier, by having the contacting surfaces contaminated by dirt, toner, or other debris. Furthermore, such metal contacts tend to oxidize forming an insulating layer on the contact surface thereby further degrading the reliability and performance of the contact.
To address these and other problems, and with recent emphasis toward the goal of replacing conventional wire harnesses and connectors in copier products to achieve a so-called "wireless copier", what is needed is an electrical interconnect that is sufficiently flexible to enable molded plastic circuits to be assembled, at will, around corners, if desired, and which can provide mechanical support between the interconnected assemblies, as well.